How to get customer group id by username without login?

Question

I have been creating one custom module for block some customer group to wholesale store. we can get customer group id by current session like

$session = Mage::getSingleton('customer/session');

 // Get the Customer Group ID.

$group_id = $session->getCustomerGroupId();

But i want to block those customers before login. How to get customer group id by $login['username'] before setting session? Anybody have an idea? Please help me guys!

Answer 1

$customer = Mage::getModel("customer/customer");
//$customer->setWebsiteId(Mage::app()->getWebsite()->getId());
$customer->loadByEmail($customer_email); //load customer by email id
echo $customer->getGroupId(); 

Answer 2

$collection = Mage::getModel('customer/customer')
              ->getCollection()
              ->addAttributeToSelect('*');

$result = array();

foreach ($collection as $customer) {
    $result[] = $customer->toArray();
}

Now $result having information of all customer in your store.